Partial regression of duodenal lesions of intestinal follicular lymphoma after antibiotic treatment.

A 51-year-old man was referred to our hospital because of duodenal lesions of lymphoma. Endoscopy showed multiple tiny smooth whitish granules in the second portion of the duodenum including the papilla of Vater. Biopsy specimens showed medium-sized centrocyte-like cells forming lymphoid follicles, and immunohistology showed positive staining for bcl-2 and CD10. A small bowel series showed multiple granular lesions extending from the second portion of the duodenum to the proximal jejunum and the proximal ileum. On the basis of these findings, the tumor was diagnosed as stage I follicular lymphoma (FL). Although the patient was negative for Helicobacter pylori, he underwent antibiotic treatment. The lesions improved 3 months after antibiotic treatment, but biopsy specimens showed residual lymphoma cells. The patient therefore received combination chemotherapy with rituximab. Endoscopy 4 months later showed regression of FL, and there was no evidence of recurrence during 3 years of follow up. The partial regression of duodenal lesions of intestinal FL may be due to the effect of antibiotic treatment.